The invention generally relates to an arrangement to prevent a premature ignition of an active charge that is to be ignited by means of an adjustable time-delay fuse and is provided for a projectile that is expended from a firing barrel by means of a charge.
More particularly, the present arrangement comprises a pyrotechnical delay element that can be ignited while firing and in turn ignites the active charge. The arrangement includes an acceleration probe located in the safety position, and during acceleration of the projectile to a specified firing velocity such probe moves as a consequence of its inertia against the firing direction into an end safety position. A barrel probe movable at right angles to the firing direction can be moved out of its safety position with the projectile shell into an armed position in which it projects laterally beyond the jacket of the projectile. The delay element and the active charge interact for ignition only if the acceleration probe and the barrel probe are simultaneously in the armed position.
In German Pat. No. 35 43 939, the acceleration probe and the barrel probe are clamped into an arm position. The acceleration probe is coupled by means of a locking bolt to a spring-loaded delay-action probe, and a communicating charge, which can be displaced by a spring braked by a jamming member, is located between the delay element and the active charge. The object of this arrangement is that, when the discharge has exceeded the specified allowable maximum acceleration or when the projectile accelerated to the specified maximum acceleration has dropped below the allowable deceleration in the firing barrel, the active charge cannot be ignited, thus availing a barrel burst. In addition, with a faulty delay element or faulty adjustment of the time-delay fuse the active charge cannot be prematurely ignited before reaching a specified safe distance of the projectile from the firing barrel which takes into account the current safety regulations requiring independent physical values for safety.
However, production of this arrangement is difficult and costly owing to the comparatively expensive construction and the requirement of precise coordination of the springs that are used.